1. Field of the Invention
The invention relates to an apparatus and to a method for aligning scoring tools and for scoring glass, in particular thin glass, along intended scoring lines in preparation for score and break separation. The invention furthermore relates to glass substrates, in particular thin glass substrates, produced by such method.
2. Description of Related Art
Thin glass particularly refers to sheet glass having a thickness in a range between 1.2 mm and 3 μm, which can be manufactured in the form of a glass ribbon or glass film and can be wound. In the context of the present application, thin glass in particular refers to plate-shaped or ribbon-shaped or film-like glass with a thickness of not more than 400 μm, not more than 145 μm, not more than 100 μm, not more than 50 μm, not more than 30 μm, not more than 20 μm, but with a minimum thickness of 3 μm, or of 10 μm, or of 15 μm being met. Ultra-thin glass (UTG) has a wall thickness of less than 150 μm.
Thin glasses are used in many fields of technology, for example in displays, in windows for optoelectronic components, in encapsulations of components, and in electrically insulating layers, and also in the field of photovoltaics. For this kind of applications, small thin glass plates are required. However, thin glass is mainly produced as a glass ribbon or glass film, and recently thicknesses of less than 350 μm are demanded. When such a thin glass ribbon or such a thin glass film is to be processed into smaller thin glass plates, numerous handling problems are encountered, for example, with respect to singularization or handling during further processing.
For example, there is a risk of premature and unwanted breaking of the thin glass due to unintentionally introduced initial damages leading to reduced edge strength. To address the risk of premature breaking along the score, the prepared scores must have a predefined quality. The scores should have a depth as uniform as possible, that means the scoring tool has to be guided precisely along the intended scoring line and with the most consistent scoring contact pressure force possible. In a thickness range between 1.2 mm and 150 μm this is feasible because of the comparatively high scoring contact pressure force to be set for scoring. However, if even thinner or ultra-thin glass is desired to be scored and the scoring contact pressure force applied to the thin glass must assume very small values, there is an increasing risk of causing unwanted surface damage.
If a diamond needle is used as a scoring tool for scoring very thin glasses having a thickness of less than 50 μm, the edge of this needle need to be precisely aligned in the direction of advancement. The alignment is usually made manually on the basis of markings on the tool and is therefore very complicated and time-consuming.
In the field of further processing it is often desired to be supplied with thin glass not in the form of small prefabricated thin glass plates, but rather with thin glass in the form of a plate or wound into a roll and prepared for being separated into small thin glass plates. However, in the case of pre-scored thin glass there is the concern of premature breaking along the scores. Already a single fracture may seriously disturb the further processing process, since glass particles might be produced which make further processing considerably more difficult.